The built feels wrong to me, unless you were laneing/splitpushing vs a ranged champ.
Steraks sadly is overall in a rather weak spot, same with zz'rot, and Zz'rot is a splitpush item that mostly helps your tower dps. Nasus one big strength is his tower dps, so he doesn't really need extra help with that.
Glory is a teamfight item, you use it to get into the fight, it's rather usless in a splitpush(unless you face an ranged opponent that else clears waves from save distance), so useing that alongside Zz'rot is wierd, either you want teamfights so why Zz'rot, or you want splitpush, so why glory?
If you want the splitpush, replace glory with Deadmens(actually really helpfull for getting away from a collaps), Consider banner over zz'rot, it can actually afk push, and it tanks towers so you can use your dps, and it's cheaper, consider Mercurial, the extera Lifesteal helps in the 1v1, the QSS active can help with your cc issue and the other stats are atleast decently usefull, not sure if Warmongs is needed, usually your passive+Q is quite high sustain, thoguh i can see why you would want it, not much other options for raw health.
Once you get ~500+ stacks, consider getting titanic hydra, cause at that point it's more important to shove a wave onto a tower and smash it than to further stack up your Q.
And get stoneplate unless you really have issues in the 1v1. That item is busted and it's mandatory if you want to survive in teamifghts, and it also helps alot when 3 man collpas onto you.
Also, i asume you run flash like 99% of all players. Imo Ghost is far better on nasus, it pairs really well with his ult, allowing you to stick to your opponent for the full duration and abuseing the low cd Q, it also has lower cd than flash, so tradeing summoners is fine, and it give better chances at running away from a collaps if you survive the initial burst or spot them early enough on a ward.
Also, if you are splitpushing, either ward that side of the jungle, or play very carefully and allways check the map for missing opponents. If you only see 2 members on the map, chances are high that the over 3 plan to rape you.
But mostly, play save till the rest of your team applies some preassure somewhere else, so your opponents would loose something on the other side of the map if they send to many people to stop you. If needed, tell your team to group and preassure a lane or dance around dragon/baron, though it is difficult to get that right in soloQ, often enough they would over do it and fight 4vs5 and loose horrible rather than avoiding fights while still staying close enough to punish your opponents should they send 2+ to stop the splitpush.